Description General description A cell-permeable, peptide vinyl sulfone that acts as a potent, irreversible inhibitor of proteasome activity. Covalently modifies the catalytically active β-subunits of the proteasome. Shown to inhibit the chymotrypsin-like (10-50 nM), trypsin-like (1-5 µM), and the peptidyl glutamyl peptide hydrolyzing (PGPH) (0.5-1 µM) activities of purified 20S proteasomes from rabbit muscle. Inhibits proteasomal degradation of deglycosylated MHC HLA-A2 heavy chain in US11+ cells (~50 µM). A potent, covalent, cell-permeable, irreversible inhibitor of chymotrypsin-like (50-100 nM), trypsin-like (1-5 µM), and PGPH (0.5-1 µM) activities of the 20S proteasome. Packaging 250 μg in Plastic ampoule Biochem/physiol Actions Cell permeable: yes Primary Target chymotrypsin-like activity of the 20S proteasome Product does not compete with ATP. Reversible: no Target IC50: 50-100 nM against chymotrypsin-like activity of the 20S proteasome Packaging Packaged under inert gas Warning Toxicity: Standard Handling (A) Reconstitution Following reconstitution aliquot and freeze (-20°C). Stock solutions are stable for up to 3 months at -20°C. Other Notes Kessler, B.M., et al. 2001. Chem. Biol.8, 913.